The ever increasing need for on line, real time and compact analyte identification for example in the area of medicine, may be answered by the use of MEMS and/or MEOMS, or Micro-Electro-Optical-Mechanical Systems technology.
It is known that spectroscopy in general and absorption spectroscopy specifically, may be applied for the purpose of analyte detection as has been shown in the past in numerous publications and patents.
FIG. 1 is a schematic block-diagram representation of a known prior art 100 for the analysis of a sample by spectroscopy. In principle, spectroscopy employs upstream illumination means 10 as a source of radiations that are beamed onto a sample S. The radiation(s) exiting the illuminated sample S usually takes advantage of optical guiding means 11, such as optical fibers elements for example, to reach a photo-spectrometer unit 20, or PSU 20.
In broad terms, the photo-spectrometer unit 20, or PSU 20 could be described as including optical means 12 and electronic means 13. The optical guiding means 11 thus lead radiations to the optical means 12 including the optical elements 121. Radiations exiting the optical elements 121 are directed onto wavelength separator means 14, which is also an optical element 121, where the received radiations are separated into rays of different wavelength, if necessary. Although not shown in FIG. 1, further optical elements 121 may be added downstream of the separator means 14.
Radiations now travel from the optical means 12 to the electronic means 13 which include electronic elements 131 such as photo-electronic means, processing means and electrical and/or electronic circuits.
The detection means 15, which is an electronic element 131, receives the output of the separator means 14 and takes spectral measurements that are fed into appropriate signal processing means 16 from which they emerge as spectrometry result output signals 17. Although not shown in FIG. 1, electrical and electronic circuits may be included into the processing means 16, or be separate therefrom.
In practice a spectroscopy system 100 as shown in symbolic form in FIG. 1 includes a plurality of elements and components that are mostly fabricated separately and thereafter, need to be carefully optically aligned and assembled. This explains the size and the cost of such devices, which become even more expensive when miniaturized.
Background art US patents exemplify the complexity of previously known spectroscopy systems and spectrometry devices.
U.S. Pat. No. 6,608,679 to Chen, et al. discloses a method for spectrophotometric analysis defined in a monolithic substrate and comprising a movable support structure on the monolithic substrate. Chen, et al. thus divulge an assembly that has a moveable structure.
U.S. Pat. No. 7,061,618 and US Patent Application No. 20060187461 both by Atia, et al., disclose integrated spectroscopy systems wherein a source system, a Fabry-Perot filter system comprising a MEMS tunable movable mirror die, and a detector system are integrated on a common bench, in a common package. Hence, Atia, et al. divulge an integrated spectroscopy systems assembled on a common bench and having moving parts.
In US Patent Application No. 20060092414, Geshwind, et al. teach a spectral measurement device and recite a spectral measurement system assembly, which is a solid state device with no moving parts. However, a spectrometer assembly of elements is different from a monolithic photo-spectrometer device.
US Patent Application No. 20060232781 by Kranz et al. divulges a miniature Fourier transform spectrophotometer wherein after fabrication of the microoptics bench 3, the microoptical components forming the interferometer are placed into their respective mounts and attached with a UV-curable adhesive. The mounts on the microoptics bench perform both alignment and attachment functions. The spectrophotometer disclosed by Kranz et al. is thus an assembly of components.
US Patent Application No. 20060262303 by Bonne, Ulrich, et al. discloses an optical micro spectrometer implemented as a wafer-level assembly using a grating and compact light source, which is applicable to fluid composition analysis. Bonne, Ulrich, et al. thus divulge a small size assembly of wafers.
The background art does not implement a spectroscopy system 100 having a monolithic photo-spectrometer structure 20 without moving parts, built as a chip of substrate material including integrally formed optical means 12 and electronic means 13, and made by only a two fabrication process steps, to provide a miniaturized monolithic photo-spectrometer 20 for use ex-vivo and in-vivo.